Jaicen

You won't register a change in voltage with the brightness control, it's acting as a current limiter. LED's don't really respond well to changes in voltage, more current usually = more brightness. As TK said, i'd put in a bigger pot, maybe get hold of a 100K multi-turn pot, i'm sure that'll solve your problem.

This is apparantly a common occurance with the old C64 PSU's.They have passive rectifiers and an RC network to filter and bring the voltage down to +5vDC. Over time the components wear out leading to higher voltages which results in lots of dead C64's with damaged RAM chips such as the one I just fixed. (I'll happily take any broken C64's and VIC's anyone has ;) ). In the case of a power supply for the MIDIBox, the voltages are being externally rectified using an LM317 (I think), which will rectify the voltages down to the correct level regardless of the input voltage (within reason). You could probably pump 9V at 1A through before it shut down, which it will as it's internally voltage and temperature protected. In short, don't worry! As long as the rectifiers are in place nothing will get damaged.

Actually, it's remarkably easy to put some parameters such as TUNE or DECAY under CV control using just a resistor and a transistor. How you'd interface the CV to the sequencer I don't know, I guess you could have an 'Automation' track or something.

Excellent! Count me in for a set then!

Ok, so i'm just about ready to crack on with building my first MBSID, having designed my CS etc. I've got a number of PIC's, but unfortunately they don't have the bootloader burnt to them, so I was wondering if there's anybody in the UK that can burn them for me. If so, i'm sure we can come to some arrangements regarding a trade or something.

It occured to me that my explanation of the layouts was not exactly clear, so I've done a little demo to show how I plan to have the PCB's mounted beneath the control surface. I think I may have to modify the spacing on the encoder pins, but it should work just fine. As you can see, on the right hand side, I intend to have two buttons and five LED's. The CS will take up half the keyboard space on the case, the other half being taken up by the LCD and menu encoder. There should also be a little room to add stuff in the future, so it's pretty flexible in terms of layout.

Since i've now had a response to this thread I figured I may as well get the designs finished and uploaded. I've not checked them thoroughly, but i'm fairly sure that it's all correct now. As you may be able to see, there are two boards, one large to hold all the encoders and associated buttons, and another smaller board which holds another DOUT shift register and a couple of buttons & LED's to show which SID (1/2) and which voice (1,2,3, EXT) is active. DOUT J1 should be connected together on both boards, as should FUNCTION BOARD J1, DOUT CORE connects to the core module (well DUH!). The DINX4 numbered jumpers all connect to a DINX4 module, which is itself connected to the core. I've not made a PCB for the LCD as I'm not sure on the dimensions etc, and it's easy enough to do anyway. Therefore DINX4 J7 & J8 are reserved for the LCD.

it's not a bug, I just didn't feel the inclination to export out the image and make it presentable. It's not really finished yet, still a couple of bugs to iron out but otherwise I think it should be fine. I won't release anything till i've finished it and (hopefully) prototyped everything. I wouldn't mind a full control surface eventually, but the amount of extra effort that entails is just a little too daunting for me. This design is more or less compatible with the full CS anyway should I upgrade, but I think that's unlikely. I may decide to add the LED Matrix as well, as it looks useful and ergonomic but we'll have to see. By the way, the panel layout I uploaded is just to give an idea of where everything is, it's not how I plan to have the CS look!

It seems this thread stalled at about the same time my investigations did. I managed to extract some of the patches from the game (sonic), but they had no resemblance to the sounds at all, so that was a bit of a dead end. I think I need to either find someone who knows how the game programmed the sounds, or look up the tech details for how the MD accesses the chip and see what I can find out.

For all those that have bought job lots of old soundcards, i'm wondering if anyone has ever come across any cards that have the YM3526 or YM3812 chip on them? I need a few for a project i'm working on to clone the SFX expander cartridge for the C64. I can source a few NOS 3526's but not the accompanying A/D chip (YM3014 or equivalent apparently). Any ideas??

Hey Smash, while we're on the topic of your LCD's, I was wondering if you were planning to get the Amber and Red backlight versions in. I really want a red one for my project, but i'd like to get it from you as I know it will work. Failing that, I was thinking of changing the LED's for different colours. If it works anything like a Cell Phone backlight, that should be reasonably simple right? I see you mentioned the LED's are through hole, does that mean they're full size and not SMT LED's??

Ladies and Gents (are there any ladies here? ??? )! I just thought I'd share the fruits of my labours so far with regards to my MBSid design. I wanted to have a cut-down control surface with access to the most important features, but without the options I don't need to tweak that often. I considered adding a matrix, but it would have meant another Din module so I left it out. Basically, this surface can be realised with just a single DINX4 module and two DOUT chips. The control surface PCB which holds all the encoders and switches (no mess of wires!) also houses a 74HC595 which handles all but two of the onboard LED's. There's another 74HC595 on a smaller board to go on the right side of the case which will also house the SID 1/2 selectors and the Voice selector and associated LED's. I'd originally planned to put all the DIN and DOUT circuitry on the PCB, but it would have meant using a double sided board, so I decided against it. At least this way, it can be added as an option by anyone with an existing StepA/B SID. All the wiring connectors are compatible with the DINX4 modules sold by Smash (as far as I'm aware), so it can be a true modular system. Still to come is a layout to hold the LCD and buttons, and another for the SID 1/2 etc. I'll also be writing some documentation to explain how the MBSID code is modified to accommodate the custom CS. Let me know what you think guys.

Actually I use ExpressPCB to do all my layouts. It's free and it works. Ok it's not brilliant but it's good enough for what I need. Mostly I make guitar effects layouts, but I think it's more than adequate for my needs in this case. c0nsumer, don't bother making up a pdf, it'll only confuse me ;) I'll do it the old fashioned way. Hopefully i'll be able to do it all on a single sided board too, since size is less of an issue for me. Thanks anyway.

I don't use eagle, hence the request for the PCB being exported as a PDF. Basically, I figured you could save me a little time since you've already laid out the tracks for everything, it means I don't have to! The PCB i'm designing is going to be pretty compact as it is, probably somewhere in the region of 10x3". The idea is that it will fit underneath the existing keyboard cutout. That way it will retain more of a C64 look and be nicely recessed. I might square the cutout up a bit though, not sold on the offset sides.

Hey man, that's some nice work! Is there any chance you could make up a .pdf or something with your LCD design on?? (Parts layout and PCB artwork). If you don't mind, i'd like to incorporate it into my StepA+ design along with encoders for ADSR, Filter etc. Could be a useful addon for your NUXX project perhaps.

Not only is that insanely cool, but your documentation is also top notch! Great project! ;D

Hey guys check this out! http://cgi.ebay.com/Commodore-VIC-20-SMPL-console-keyboard-RARE_W0QQitemZ190011482111QQihZ009QQcategoryZ74945QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Apparently it's some sort of master clock/MIDI controller based around a VIC20. As used by Peter Gabriel no less (well, not this actual unit obviously). Useless without the accompanying cartidge, but still very cool! 8)

Is that a hint guys?? MBSID V2 perhaps?..... ::)

Very clever indeed! I'm looking forward to seeing it released!

Am I right in thinking that the up-coming MBSID V2 will support two SIDS per core in a similar fashion to the SID2SID? Ie, using the CS pin?? That would save a whole lot (well, not that much ::) ) of components (ie, no second core!).

I just wanted to note that I got my chips in the mail today. Took less than a week to go halfway around the workld, so that's not bad! Haven't tested them yet, but they look well protected.

Yeah, when the strat was released, Leo named the vibrato arm a tremolo arm, because someone had already patented Vibrola or something.

You should look up the datasheet for the 25xx series, as the external logic is different. I don't know exactly how you're planning to address it either, it's not very clear. Check out Andrew's design to see how it's possible to address two loops with one switch. With regards to running to the end of the capacity, unless the chip reads an EOM marker, it'll keep going to the end and stop, it won't loop unless it gets an EOM. Finally, the low sample rate is more to do with the technology itself than any restrictions imposed by the manufacturer. It takes time to store the sampled audio and this is the limiting factor, which is all in the datasheets on winbond.com.

I'm all for it in fact! I've been wanting to build my own MIDI synth for some time, but I don't have the confidence to pull off something like a Mini-Moog. Nor do I want the hassle of true analogue VCO's which drift with temp etc. My ideal synth would have a DCO like the Juno, and the analogue filters from an MS-20. Actually, if you've ever heard a SIEL MONO, that's a brilliant synth which mixes different width pulses to make interesting waveforms. They're only £200-300 though, so i'm not sure it's worth DIY'ing! Aaaanyway, back on topic! All the stuff needed to control an analogue synth is available on ucapps. For example, a single core and AOUT board can control up to 8 different oscillators with minimal coding, so it's not difficult!

This is all Leo Fender's fault actually. He intentionally used the terms tremolo and vibrato wrongly because he thought it sounded better in his ad copy.